As the performance of microprocessors increases over time, designers face an increasingly difficult heat generation problem. Clock throttling, the reduction of a processor's clock frequency when the processor generates too much heat, is one approach for reducing processor heat generation. While clock throttling can successfully prevent overheating in single core processors, this approach may substantially negatively impact processor performance.
Multi-core processors, namely those processors with multiple processor cores on a common integrated circuit die, may also experience significant heat generation problems. As the number of cores on a die increases, designers find it increasingly challenging to provide sufficient power and cooling to all of the cores in a manner that provides optimal performance. Multi-core processors may employ clock throttling to prevent overheating, but once again this approach sacrifices processor performance.
As multi-core processors proliferate and increase in speed, the problem of providing sufficient power to supply multi-core processors with the large switching currents they require becomes more difficult. Thermal density becomes even more significant as the semiconductor die size of multi-core processors decreases in some applications. In some cases, when the processor constantly uses a particular core to execute instructions, a hot spot develops on the semiconductor die at the location of the particular core. Local overheating of the die and processor failure may result from such a hotspot. To address this problem, conventional processors may set sufficiently low operating frequencies to ensure sufficient guardband so that these undesired conditions do not occur. Unfortunately, this approach may substantially limit the performance of the processor.
What is needed is a multi-core processor that manages the production of heat by the cores thereof.